The figure is a bar graph illustrating the use of nonmedical opioids (NMOs) and heroin among 68,000 students based on gender. The horizontal (x)-axis shows the type of drug used. The vertical (y)-axis shows the risk of drug use, expressed as the adjusted odds ratio. Drug users are divided into three groups: those who have used NMOs at least once are represented by a one-pill symbol; those who have used NMOs at least 40 times are represented by a two-pill symbol, and those who have used heroin at least once are represented by a syringe symbol. In the figure, male students are represented by blue bars and female students by red bars. The left pair of bars shows the adjusted odds ratio for male and female students having used NMO at least once. The adjusted odds ratio for male students has been set to 1.0; the adjusted odds ratio for female students is 0.79. The middle pair of bars shows the adjusted odds ratios for having used NMO frequently. The adjusted odds ratio for male students is set at 1.0, and the adjusted odds ratio for female students is 0.59. The right pair of bars shows the adjusted odds ratios for having used heroin at least once. Again, the adjusted odds ratio for male students has been set to 1.0 and the adjusted odds ratio for female students is 0.57. Thus, male students were more likely than female students to report NMO and heroin use, with greater differences reported for frequent NMO use and heroin use than for lifetime NMO use.